vips: build PNG support using libspng instead of libpng

This has better performance and is the upstream libvips preferred option.

+2 -3
+2 -3
pkgs/tools/graphics/vips/default.nix
··· 22 , libtiff 23 , fftw 24 , lcms2 25 - , libpng 26 , libimagequant 27 , imagemagick 28 , pango ··· 79 libtiff 80 fftw 81 lcms2 82 - libpng 83 libimagequant 84 imagemagick 85 pango ··· 101 102 mesonFlags = [ 103 "-Dcgif=disabled" 104 - "-Dspng=disabled" 105 "-Dpdfium=disabled" 106 "-Dnifti=disabled" 107 ] ++ lib.optionals (!stdenv.isDarwin) [
··· 22 , libtiff 23 , fftw 24 , lcms2 25 + , libspng 26 , libimagequant 27 , imagemagick 28 , pango ··· 79 libtiff 80 fftw 81 lcms2 82 + libspng 83 libimagequant 84 imagemagick 85 pango ··· 101 102 mesonFlags = [ 103 "-Dcgif=disabled" 104 "-Dpdfium=disabled" 105 "-Dnifti=disabled" 106 ] ++ lib.optionals (!stdenv.isDarwin) [